The invention relates to a method for producing security elements, security elements, a security document with at least one security element, a transfer film with at least one security element as well as a laminating film with at least one security element.
Optically active security elements are used in particular on security documents such as for instance banknotes, passports, ID cards, check cards, credit cards, visas or certificates for both information and decorative purposes. Security elements of this type on the one hand increase protection against forgery for example vis-à-vis modern color copiers and other reproduction systems and on the other hand can be easily and clearly recognized by the layperson, with the result that the layperson can clearly determine the authenticity of a security document provided with a security element of this type and can thus recognize forgeries or manipulations.
For this purpose, security elements can have light-bending, diffractive structures such as for example holograms. Optical effects that are particularly striking and therefore memorable for the layperson are brought about, in particular, by representations having a spatial effect for an observer, which are produced, for example, by transmission holograms. However, holograms of this type have the disadvantage that the spatial representation of an object produced by them is heavily dependent on the illumination conditions and as a result of this they often have inadequate brilliance, in particular under illumination conditions which are not ideal, such as for example predominantly diffuse daylight. Thus, for sharp three-dimensional representation of an object, holograms of this type for example must be illuminated with a monochromatic point light source, such as for example a laser pointer. Furthermore, holograms of this type necessitate comparatively high equipment costs for the production of the master needed for a replication in corresponding layers. There is also, generally, no possibility of increasing the attractiveness of a corresponding optically variable element by additionally achieving particular color effects or color perceptions.